Box Spanner Fix

[mzt]

Some days ago, I had to apply a pipe to the handle of the box spanner I’m using on the mill, to remove an overtightened drill chuck:
ended with the business end of the spanner breaking into pieces, luckily the chuck was released at the same moment.

This is definitely not a fix, but I needed something made quickly (and it is still working after a few days. Might end up with
press fitting a collar to this one, someday)

Box Spanner Fix

 
But I want a more durable one (though the above one reminds me not to overtighten the chuck ANYTIME I’m using it).

Started with this

Box Spanner Fix

 
And drilled thru a portion of it to the distance between the flats of the square on the drawbar (8mm),

Box Spanner Fix


then some length of it to the distance between the opposite corners (10mm)

Box Spanner Fix

 
A quick visit to the marking bench

Box Spanner Fix

 
Then to the mill, to drill the four 1.5mm dia holes (some 12mm deep)

Box Spanner Fix

 
Took a picture of the other end, too, toghether with the next tool I’ll use, tomorrow.
(I wish I kew where the square file is gone: will do with the triangular one with a little more care).

Box Spanner Fix

Passing close to the vise, on my way to bed… ..it’s almost done now, but no pictures yet.

Marcello

[Stilldrillin]

After some careful filing, that will be a great repair Marcello! 

David D

[mzt]

The spanner shaft (a 12mm bolt, should be strong enough for the job) turned to .07mm interference fit,
drilled for the handle, tapped for a set screw.

Box Spanner Fix

 
Now in the press, barely within the envelope of the machine
 
Box Spanner Fix

Here it is! I’m definitely satisfied with the fit and finish of the square socket.
May add a taper pin, or have somebody welding the parts together, someday.


Box Spanner Fix

Marcello

[mzt]

Now I have a working replacement wrench, I can take the risk of fixing the broken one, finally.
First of all, I removed the jubilee clip and paper tape that were holding the loctited part in place,
then put it into the lathe to gain a round end: was not sure about applying intermittent cuts to a glued part,
but it did not move. That material is glass hard, btw. 

Box Spanner Fix

 
Next, I turned an alu. collar to press fitting diameter. I suppose steel would have done better, but there
were some alu. tubing odds into the box: too tempting.

Press-fitting the collar. 

Box Spanner Fix


The finished job.

Box Spanner Fix

 
As for the homemade one, I managed to fit an 1/8" taper pin in it.

Box Spanner Fix

I measured the diameter of the pin at (A) and (B), then divided the distance from A to B by the number of drills
I had... then it was only a matter of applying enough force to have the pin squeezed down the stepped hole.


Marcello